The National Weather Service says cold air is firmly entrenched over the Gulf states, with north winds blowing over extensive snow pack farther north.

This will produce hard freeze conditions across most of south Louisiana and southern Mississippi, the weather service says. A light to moderate freeze is even anticipated as far as the coastal marshes of southeast Louisiana and areas south and west of the tidal lakes.

The weather service warns that temperatures will fall quickly as the sun sets, with most locations near freezing between midnight and 3 a.m.

Friday morning lows will range from the upper 20s to the lower 30s with a few locations possibly falling into the mid 20s.

Temperatures should warm above freezing before 9 a.m. Friday, meaning that many locations will see below-freezing temperatures for six to eight hours.

Sub-freezing temperatures can kill sensitive vegetation. Pets are also subject to extreme cold and should be kept indoors.